`Did I request Thee, Maker, from my clay/ To mould me Man, did I solicit Thee/ From darkness to promote me?" This bitter utterance, which could in spirit be almost any unhappy child speaking to its parent, is in fact from Milton's "Paradise Lost" and serves as the epigraph Mary Shelley set at the beginning of "Frankenstein." It is relevant to Richard Powers' "Galatea 2.2" because this breathtaking novel--vast not in length but in the mental distance it takes us--is similarly devoted to the creation of an artificial being intended to rival humankind.

This time, however, perhaps reflecting the modern split between science and humanities, there are a pair of Frankensteins. One is a misanthropic professor of computer science named Philip Lentz, a sly, sadistic man; the other, the semi-autobiographical narrator, is a novelist in residence at the same university, to whom Powers teasingly gives his own name and what may well be his own history.

The narrator Powers is credited with the novels Powers has actually written; he is also given a former girlfriend, C., who befriended him when his father died and who left him in part because his writings amounted to stealing her life. A third loss is the death of a favorite professor, Powers' mentor. We have a sense that the narrator is drifting, living in a virtually empty apartment, alone on a sea of words, and that in his loneliness he is somehow vulnerable to his creation.

Challenged by a casual bet in a bar, Lentz and Powers have undertaken to create an artificial intelligence capable of responding to the Masters exam in English literature cleverly enough to pass for human. The computer can effortlessly absorb any number of standard texts, but amassing the background that makes the interpretation of literature possible is a seemingly insoluble task.

Not overstating the difficulties, Powers argues, "In order to produce a remotely plausible association matrix for six measly Tennyson lines, our candidate will need a file cabinet two global hemispheres wide." Lentz takes a more cynical view of how masters candidates read. Coming upon Powers, who is attempting to give the computer intelligence a childhood by reading aloud "Green Eggs and Ham," Lentz snarls, "Skip childhood. . . . She doesn't need to know anything, she just needs to learn criticism. Derrida knows things? Your deconstructionists are rife with wisdom? . . . Don't you know that knowledge is passe? And you can kiss meaning bye bye as well."

But gradually--perhaps too gradually for those indifferent to the intricacies of computer programming--as Powers spends nights reading literature into a voice monitor, a computer generated mind uncannily creates itself. Ideas form as words foregather. Powers christens the newborn mind Helen, after the image of dutiful beauty in a poem by Yeats. This invisible being, existing only in the charge passing electrically from computer to computer, becomes for its creator like the Galatea of myth, an object of mental desire. And yet, despite the creation's invisibility and delicacy, its dissimilarity to the crude monster of Mary Shelley's work, there is a disquieting resemblance between the two books.

In both novels the effort to construct The Other is self-defining. In what the creator thinks it necessary to include in a counterfeit human we find clues to our own nature. Lentz, for example, disdains Powers' effort to make the artificial intelligence genuinely responsive. "We humans are winging it . . . input pattern x sets off associative matrix y, which bears only the slightest relevance to the stimulus. Nobody really responds to anyone else," Lentz taunts.

In "Galatea 2.2" we find that most of the defining characteristics of human thought are not glories but quirks, limps, the scars of sad experience. It is, for example, precisely the ability to stand apart, in a skeptical relation to one's own knowledge, that Helen lacks. Her mind is straightforward, incapable of using or understanding sarcasm, which is Lentz's forte, or humorous irony, which is the narrator's specialty. The rueful joke that ends a passage in which Powers describes the textbook from which he learned Dutch, would be lost on his creation. "On one page a passage spelled out some aspect of life in dit kleine land. On the next page the same story appeared with every fifth word missing. Story of my life."

Incapable of lying, self-deception or illogic, Helen seems innocent--like a child before it knows the routine wickedness of the world. Remote from need and passion, the created mind has a nobility that makes us feel protective of it.